Depending on the processed material from each drill must be properly sharpened. To verify the correct angle will help a specially prepared square plate of copper or aluminium with a thickness of 1 mm.
To become operational protractor enough to cut it cut, as shown in the picture: a large cutout at an angle of 120 degrees, the other half is 60 degrees and the surviving corner of a square is 90.
Recommend to read
THE TICKLER SPRING
It is convenient to create a temporary memo — whether it is preparing the card for your file, or just notes about the latest Affairs in the coming days, or envelopes with letters...
ACCORDING TO THE PRINCIPLE OF COMMUNICATING VESSELS
...it is possible to make a device for determining the marks in the construction of garden buildings. For this you will need a long hose with transparent bits filled with water.
